Pressure distillation of hydrocarbon oils



Jan. 1, 1929. l 1,697,573". F. M. ROGERS ET AL PRESSURE DISTILLATION OF HYDROCARBON OI'LS Filed Nov. 17. 1922' 'Patented J. l', 1929.

i T i A CORPORATION F INDIANA.

PRESSURE`DISTILLATION OF 'HYDROCARBON OILS.

Application filedA November 17,119.22, Serial No. 601,485, and in Canada May 26, 1924.

This invention relates to'y improvements in methods for the pressure distillation of hydrocarbon oils lfor the production of lower boiling point products, for example, of the nature of gasoline. and `will be fully understood from the following description. illustrated by the accompanying drawings, inl which l 'e Figure 1 shows, in part diagrammatically,

apparatussuitable for carrying'this invention into eject. Figure 2 is a transverse sectional view through the dephlegmating or reflux tower shown in Fig. 1 on line 2 2 of the latter figure.

In the apparatus illustrated. the numeral if), indicates the end of asuitable container or still in which the hydrocarbon oil to be subjected to the process is brought to a conversion temperature under the pressure conditions.

From the still 5, the vapor line 6 leads to a reflux or ,deph egmating device 7, which ,A may be of any suitable construction. In the apparatus illustrated. it is shown as a screen baille tower, in which are arranged a series of transverse screen ballles S. which extend partially acrossA the tower. The tower may be exposed or may be provided with a heat insulating coating as desired, the latter form being preferred. From the reflux device 'i' uncondensed vapors pass out through the vapor pipe 9. The reflux device 'a' is maintained under the same pressure as that prevailing in the still 5. In practicing the present invention, the pressure upon the apparatus may be relieved beyond the -con- Vdenser, as shown in the patent of William M. Burton. 1.019.667. of January 7 1913 or it may be reliev3ed between the reflux device and the condenser. as more fully described in the patent to Humphreys and Burton, 1.343.674, of June 15. 1920.

The .condensate or reflux formed in the dephlegmator, 7 is returned to the 'still\ through the run-back line 10.A Oil is pumped into the reflux device, preferably near the top. in the manner more fully hereinafter described, through the pumping-in line 11, which is provided within the dephlegmator with av suitable distributing 'device or spray head 1Q.

In carrying out the present process. the

i still 5 is charged with the hydrocarbon oil to be distilled, which is first gradually heated through the run-back line prevailing.

products pass out of the 16, 1915. In this.manner, the distillation of the hydrocarbon` oil before it reaches its proper operating temperatureis prevented.4

'hen the operating temperature isi-cached, the vapors evolved from the still 5 l pass through the vapor line 6 into the dephlegmater-'7, inwhich products having a higher boiling point than the desireddistillatel pro- WRITING, INDIANA, AssIG'NoRs ducts are condensed and returned to thei still l 10. The uncondensed vapors of the desired low-boiling dephlegmator throughthe vapor line 9 to a suitable condensing Asystem (not shown) in which the desired roducts are condensed.' At the same time, a ydrocarbon oil having characteristics closely similar to the low boiling products thus condensed is pumped into the dephlegmator through the, pumping inline 11. these products being substantially completely vaporized in .the dephlegmator I and their vapors passing out together with the vapors of the desired low-boiling products evolved from the still 5. The proportion of the low-boiling oil .thus introduced into the dephlegmator 7 may vary upwardly from an amount equal to the amount of low-boiling productproduced within the still 5 within wide limits. say up'to 4 or times the amount so produced. lThe applicationof heat to the still 5 is controlled to cause t'he evolution of the desired volume 'of low,- boiling products. It has been uniformly found v that the greater -the proportion ofv I .low-boiling oil pumped into the reflux device in the manner described, the greater is the proportion `of low boiling products evolved from' the still.

when if. is desired' to feed im@ 111e Suu during its operation, stock of a character similar to the stock charged into the still;l

that is, stocl heavier than the desired low boiling products, this feed stock may be supplied through the same pumping-in-line 11 or may be pumped directly intothe'still.

As a s pecic example of the operation of' tains approximately 60% the present process, given. The still 5 petroleum oil havin of say from 450 to operating conditions havebeen established, a part of theydistilla-te itself is pumped into the d ephlegmator 7 through' the line l1. Under these conditions, with two hundred gallons of such distillate evolved per hour per hour are pumped in through the line 11, a distillate having an end point of 450, 58% of which boils off at 8740 F.. is obtained. When 250 gallons of 4the distillate y are pumped in per hour, the evolved Ydistillate has an end point of 440 to i450 F. and con- F: When three hundred gallons per h our of the distillate are pumped into the line 11, a distillate having an end point of 430 to 435 F. is obtained containing above 70% boiling off at 374F. Further increases in the proportion of the product boiling oli' at 374 .be understood, of course,

areobtained by increasing the proportion of distillate pumped into the line 11. It will that substantially the entire-amount of distillate so pumped in is vaporized and passes out of the system with the vapors of the low-boiling products formed in the still and the amount of distillate actuallyr produced is calculated with the deduction for the proportion of distillate introduced through the line'll.

Ve claim:

-1. A method of distilling hydrocarbon oil for the formation of low-boiling products,

which consists in heating such oil under'A pressure to a conversion temperature, introducing into the vapors evolved by the oil, liquid hydrocarbon oil having approximately the characteristices of the desired products, removing the vapors of the desired A hydrocarbon oil similarv to the distillate'and preferably, after from the still, When two hundred gallons boiling olf at 374 products together with the vapors of the oil introduced and returning to the oil undergoing heating condensed products of a higher boiling' point than the desired products.. I

2. A methody of distilling hydrocarbon oil for the formation of low boiling products, which consists in heating such oil under pressure to a conversion temperature, introducing into the vapors evolved by the oil, liquid hydrocarbon oil having approximately the characteristics of thel desired products evolved from the oil, in amount, at least equal to the amount of such evolved products, removing vapors of the-'desired products together with the vapors of the oil introduced and returningto the oil undergoing heating condensed products of a higher boiling point' than thedesired products. l

3. A method of distilling hydrocarbon oil v for the formation of loW-boilingproducts which consists inl heating such oil under pressurel to a conversion temperature, introducing into the vapors evolved by the oil, a liquid hydrocarbon oil substantially'v identical with the desired low-boiling products evolved from the still and previously produced therein, removing the vapors of the desired products, together with the vapors of the oil introduced and returning to the oil undergoing heating condensed products ofa higher boiling point than the desired low-boiling product.

4. A method of distilling hydrocarbon oil for the formation of a gasoline-containing distillate which consists in heating a body of oil having a boiling point range between 450 and 750 F. under a pressure of 5 to 6 atmospheres to a distillation temperature, introducing into the vapors evolved byy the oil While under such pressure, gasolinecontaining distillate having approximately` the characteristics of the gasoline-containing distillate produced from saidoil, removing .the vapors of the desired product together with the vapors of the oil introduced and returning to the body of oil condensed products of a higher boiling point than the desired products.

FRANCIS M. ROGERS.

EDWARD J. SHAEFFER. 

